@lacspace/idempotency
Make any operation exactly-once with an idempotency key — fingerprint the request (reject key-reuse with a different body), replay the stored response on retries, lock in-flight duplicates, and sweep expired records. Framework-agnostic, pluggable store, zero-dependency, isomorphic.
npm i @lacspace/idempotencyUsage
import { idempotent } from "@lacspace/idempotency";
// in a POST handler — the client sends an Idempotency-Key header
const key = request.headers.get("idempotency-key")!;
const { value, replayed } = await idempotent(key, () => chargeCard(order));
// first request: runs chargeCard, stores the result → replayed: false
// any retry with the same key: returns the SAME result → replayed: true (no second charge)
return Response.json(value);Exports 7
IdempotencyIdempotencyConflictErrorIdempotencyKeyReuseErrorMemoryIdempotencyStoreReplayedErrorfingerprintidempotentKeywords
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